Method and apparatus for detecting pits in fruit

Abstract

A method and apparatus for the detection of pits and abnormalities in various stone fruits. The apparatus transmits a first plurality of beams of light (18) across inspection zone (14) and transmits a second plurality of beams of light (22) across inspection zone (14) in a direction opposite to beams of light (18). As a stone fruit (10) passes through inspection zone (14), a first plurality of sensors (32) and a second plurality of sensors (34) detect the variations in the intensity of the transmitted beams of light. The light transmittance and reflectance characteristics of the stone fruit are analyzed to detect the presence of a pit or internal or external abnormality.

I claim: 
     
       1. A method for inspecting an article of produce passing through an inspection zone, comprising the steps of: (a) sequentially transmitting a first plurality of substantially parallel beams of light across an inspection zone;   (b) sequentially transmitting a second plurality of substantially parallel beams of light across said inspection zone in a direction substantially opposite to the direction of said first plurality of beams of light;   (c) alternating between transmitting a beam of light in said first plurality of beams of light and transmitting a beam of light in said second plurality of beams of light;   (d) sequentially sensing the intensity of each of said beams of light transmitted through an article of produce passing through said inspection zone, said sensing occurring along the axis of transmission of each of said beams of light;   (e) sequentially sensing the intensity of each of said beams of light reflected by said article of produce; and   (f) processing the sensed data to determine the light transmittance and reflectance characteristics of said article of produce based on variations in intensity of said sensed data, whereby the presence of a pit, defect, abnormality, or other internal or external characteristic of said article of produce is detected.   
     
     
       2. The method as recited in claim 1, further comprising the steps of: (a) detecting the presence of said article of produce in said inspection zone; and   (b) modulating the transmission intensity of said beams of light in response to the presence of said article of produce in said inspection zone.   
     
     
       3. The method as recited in claim 2, further comprising the step of alternating between sensing the intensity of each said beam of light in said first plurality of beams of light and sensing the intensity of each said beam of light in said second plurality of beams of light. 
     
     
       4. The method as recited in claim 1, wherein each of said beams of light comprise highly collimated light rays. 
     
     
       5. The method as recited in claim 1, wherein said beams of light are infrared light. 
     
     
       6. The method as recited in claim 1, wherein said beams of light are visible light. 
     
     
       7. An apparatus for inspecting an article of produce passing through an inspection zone, comprising: (a) first transmitting means for sequentially transmitting a first plurality of substantially parallel beams of light across an inspection zone;   (b) second transmitting means for sequentially transmitting a second plurality of substantially parallel beams of light across said inspection zone in a direction substantially opposite to the direction of said first plurality of beams of light;   (c) means for alternating between transmitting a beam of light in said first plurality of beams of light and transmitting a beam of light in said second plurality of beams of light;   (d) means aligned with said first transmitting means for sequentially sensing the intensity of each of said beams of light in said first plurality of beams of light transmitted through an article of produce passing through said inspection zone;   (e) means aligned with said second transmitting means for sequentially sensing the intensity of each of said beams of light in said second plurality of beams of light transmitted through said article of produce;   (f) means positioned adjacent to said first transmitting means for sequentially sensing the intensity of each of said beams of light in said first plurality of beams of light reflected by said article of produce;   (g) means positioned adjacent to said second transmitting means for sequentially sensing the intensity of each of said beams of light in said second plurality of beams of light reflected by said article of produce; and   (h) processing means for processing the sensed data to determine the light transmittance and reflectance characteristics of said article of produce based on variations in intensity of said sensed data, whereby the presence of a pit, defect, abnormality, or other internal or external characteristic of said article of produce is detected.   
     
     
       8. The apparatus as recited in claim 7, further comprising: (a) first collimating means for collimating the light rays in each beam of light in said first plurality of beams of light; and   (b) second collimating means for collimating the light rays in each beam of light in said second plurality of beams of light.   
     
     
       9. The apparatus as recited in claim 7, wherein: (a) said first transmitting means comprises a first plurality of infrared emitters;   (b) said second transmitting means comprises a second plurality of infrared emitters;   (c) said first sensing means comprises a first plurality of infrared detectors; and   (d) said second sensing means comprises a second plurality of infrared detectors.   
     
     
       10. The apparatus as recited in claim 9, wherein each said infrared emitter has an angle of dispersion of less than approximately twelve degrees. 
     
     
       11. The apparatus as recited in claim 10, wherein each said infrared detector has an acceptance angle of less than approximately twelve degrees. 
     
     
       12. The apparatus as recited in claim 7, further comprising means for alternating between sensing beams of light in said first plurality of beams of light and sensing beams of light in said second plurality of beams of light. 
     
     
       13. The apparatus as recited in claim 7, further comprising: (a) means for detecting the presence of said article of produce in said inspection zone; and   (b) means for modulating the transmission intensity of said beams of light in response to the presence of said article of produce in said inspection zone.   
     
     
       14. The apparatus as recited in claim 7, wherein said processing means comprises a programmed data processor. 
     
     
       15. An apparatus for detecting the presence of a pit, defect, abnormality, or other internal or external characteristic of an article of produce passing through an inspection zone, comprising: (a) first transmitting means for sequentially transmitting a first plurality of substantially parallel beams of light across an inspection zone;   (b) second transmitting means for sequentially transmitting a second plurality of substantially parallel beams of light across said inspection zone in a direction substantially opposite to the direction of said first plurality of beams of light;   (c) means for detecting the presence of an article of produce passing through said inspection zone and increasing the intensity of said beams of light in response thereto;   (d) first sensing means for sequentially sensing the intensity of each beam of light in said first plurality of beams of light passing through said inspection zone;   (e) second sensing means for sequentially sensing the intensity of each beam of light in said second plurality of beams of light passing through said inspection zone;   (f) third sensing means for sensing the intensity of each beam of light in said first plurality of beams of light reflected by said article of produce, said third sensing means positioned adjacent to said first transmitting means;   (g) fourth sensing means for sensing the intensity of each beam of light in said second plurality of beams of light reflected by said article of produce, said fourth sensing means positioned adjacent to said second transmitting means;   (h) means for alternating between transmitting a beam of light in said first plurality of beams of light and transmitting a beam of light in said second plurality of beams of light; and   (i) processing means for processing the sensed data to determine the light transmittance and reflectance characteristics of said article of produce based on variations in intensity of said sensed data.